I think a good replacement to the lanes map would be to bring back the river. Only this time maybe make it more of just a pond. Get rid of the slow when standing in the water, and make a bulge of shared area in the middle like a pokeball shape. The borders of the map could be square or a circle if you wanted to complete the pokeball picture. Water would fill in all of the shared area and look very nice.

I like that idea a lot. Having a circular shared area would definitely add an interesting dynamic, and of course I love anything related to Pokémon! I'd probably add back walls since it's not as much fun having the number of dodgeballs on the field too low. Maybe I'll use the new type of wall that stops dodgeballs but doesn't reflect them. Also for the center, perhaps I could add a healing element to the water. Or would that be too gimmicky?